Scale



Oct. 20, 1925- R. CRAIG SCALE Filed June 13. 1921 Patented Oct. 20, 1925.

UNITED STATES@ PATENT OFFICE.

ROBERT CRAIG, OF DAYTON, OHIO, ASSIGNOR, BY MESNE ASSIGNMENTS, TO DAYTON SCALE COMPANY, OF DAYTON, OHIO, A .CORPORATION F NEW JERSEY.

SCALE.

Application illed June 13, 1921. Serial No. 476,905..

automatic weighing scale was shown en-lV closed in a tank or housing of suchtypethat the delicate working parts were completely protected from damage due to mois- 20 ture or other .foreign substances.

Scales of the, automatic type require a dash-pot device to control their action. In the 'construction heretofore used this dashpot was within the tank or housing and in 25 order to adjust its action` it wasnecessary to remove the cover, reach into the o1l,and turn the thumb-screw.

One object of the present invention resides in the provision of means for adjusting the dash-.pot from outside the case.

Another object of the invention resides in the provision of an oil seal around the platform stern which is adapted to prevent air, moisture or other substances from passing r from the outside to the interior of the housing. y

Other objects of the invention will be set forth in detail in the accompanying specification and claims and shown in the drawings which show by Way of exemplification one embodiment of the invention.

In the drawings:

Figure 1 shows a side elevation of the scale with certain parts in section to show the interior construction. Y

Fig. 2 is a detail sectional View taken on line 2-2 of Fig. 1.

In its general details the scale is the same as the construction described in the application above referred to. It comprises an enclosing tank or housing Within which is placed a scale having a base 11, and the usual o crating parts comprising, a fulclumedv ever 12, and an indicator 13 sweeping over a chart 14. The lever is provided with `an automatic counterbalance which may bein the form of a spring 15.

The usual dash-pot 16 is provided which has its piston connected to the scale lever. Dash-pot action is controlled by a, valve device having a hollow stem surrounding the piston rod and carryin at its upper end a gear 17. Rotation of t is gear to variable extents changes the action of the dash-pot by 'changing the relation of ports in the valve plate and 4dash pot plunger. Such dash pots are Well known in the art and require no detailed description.

To eil'ect a rotation of the gear 17 and the consequent adjustment of the action of the dash-pot from Without the case, I provide a stud 18 carryinga knurle'd setting knob 19 at its upper end and carryin ay gear 20 which is adapted to be enmes ed with the gear 17 when the setting device is displaced to the dotted line position. To facilitate the enmeshment of the gears I preferably bevel the teeth as shown but plain teeth may be used, in which case the gears will slide over each other until the enmesh., lEnmeshment will be readily e fected in either case since the spring 15 ele vates gear 17 yieldin ly against its cooperating gear. After tie knob 19 has been turnedl suiciently to properly adjust the 'dash-pot the vars are disengagedyPreferably, I provide a spring 21 for this purpose, but other means may be used for maintaining the gears, out of engagement exce t When adjustments are bein made. IIt will be understood that during t e Weighing operation, the gear parts must be kept out of contact; otherwise, friction would result, which would interfere with the accuracy of the. weighing.

In the application heretofore referred t0, it is explained that the tank 10 may contain oil or may be empty. Provision was made to prevent liquids entering the case around the.

platform holder stem 22 by means of concentric guards. In the present embodiment the concentric guards 23-24 are revcrsely and telescopically arranged as shown in Fig. 1 and the guard 23 is adapted to contain oil 25 or other liquid Whlch with guard 24, forms a seal which effectually revente the entrance of either air or liquid) into the housing. To minimize the msL the platform.

The oil seaI construction may be used with either oil immersed scales or with empty tank types of scales. It affords numerous advantages with either type. For example,

it protects the scale parts which are above,y

the oil level from corrosion. Its use permits the empty tank type to be used with the same or more protection to the parts that an oil immersed type would have. Empty tank types are advantageous in that they permit the sealing of the scale in air, the ellmination of oil with its attendant expense and possibility of leakage, and the possibility of using a lighter platform.

When the tank is used empty` I nd it A desirable to provide a rubber or like diaphragm 28, which yields and prevents the compression of air within the case from affecting the weighing. The slight variation in balance due to the varying displacement of the parts in the oil of the seal can be compensated for by the usual sealing methods. To cut down this dis lacement effect the submersible parts shoul be made as thin as possible.

What I claim is: y

1. A weighing scale having movable partsand a housing completely enclosin the movable working parts of the scale and preventing the access of foreign substancesI thereto a dash pot connected to a moving part o the scale, and means for adjusting and then downwardly within the ependlng flanged portion 26 of devices which control the action of the dash pot from without the housing.

2. A weighing scale comprising loadcounterbalancing indicating and lever arts, an enclosing housin therefor, a `da -pot connected to the sca e lever and within the housing; and means for ad'usting devices .which control the action o the dash pot from without the housing;

3. In a vscale havin vt e usual operating parts, a protecting ousing surrounding said parts, a weight movedl part extendin into the housing into cooperation with sai operating'parts, a dash-pot within the housing and operatively connected to one of said operating parts, and a dash-pot adjusting device o rable from without the housing and having provisions for /adjustin the same into cooperation with the das'pot when adjustments are to be ma'de and out of cooperation therewith when weighing is to be carried out. y

4. The invention set forth in claim 3 in which a spring is associated with the dashpot adjusting devices to retract the same automatically from cooperation with the dash `ot.

A 5. he invention set forth in claim 3 in which a gearv is rovided upon the dash-pot device and inw ich a second gear is pro' vided upon the adjusting device, said gears being adapted to be enmeshed when the -dash-pot is to be adjusted.

In testimony whereof I hereto aix my signature.

ROBERT CRAIG. 

